Decompression Sickness

Decompression sickness, or the bends, can occur when the pressure surrounding the body is reduced too quickly, or after exposure to increased pressure such as during diving.

Under increased pressure, additional gases — mainly nitrogen — dissolve into the body's tissues and bloodstream.

If the pressure is then reduced too quickly, the nitrogen can come out of solution and form bubbles within the body.

These bubbles commonly cause pain in the joints, known as the bends.

Less commonly, nitrogen bubbles may affect:

• the skin — known as the creeps;
• the nervous system — sometimes known as the staggers; or
• the lungs — known as the chokes.

Severe decompression sickness can cause serious injury, unconsciousness or death.

Divers reduce the risk of decompression sickness by following safe diving procedures, including controlled rates of ascent and decompression stops where required.

Flying After Diving

Flying after diving can increase the risk of decompression sickness.

A diver may have enough excess nitrogen remaining in the body to cause no symptoms at sea level, but the further reduction in atmospheric pressure during flight may cause nitrogen bubbles to form or expand.